The optical fiber composite overhead ground wire is an important line for the electric power system communications, and is responsible for power dispatching, relay protection and many other services. At present, accident potentials on the communication lines in power industry are generally investigated by manpower inspection. This inspection mode is weak in pertinence, and it cost long time to conduct a routing inspection, so it is of low efficiency. Lightning stroke, ice covering, typhoon and the like are main reasons that lead the faults of the optical fiber composite overhead ground wire, and compared with ice covering, typhoon and the like, the faults caused by the lightning stroke on the optical fiber composite overhead ground wire are more covert. This is because if the lightning stroke does not directly lead to break of the optical fiber composite overhead ground wire, strand breakage or increased local brittleness at the lightning stroke position is hard to be found by human eyes. If the lightning stroke on the optical fiber composite overhead ground wire can be identified and located in time and the automation level of power system operation and maintenance is improved, the line inspection is more targeted, so as to save human resources, money expenditure and material consumption.
Among the present technologies, the invention patent application No. 201110214109.1 discloses a method for identifying the lightning stroke and non-lightning stroke events on the power transmission line. The lightning stroke is identified by determining the fault traveling wave current and comparing wave coda time with a threshold, but the method cannot be used to accurately locate the lightning stroke position. The invention patent application No. 200610021239.2 discloses a method for determining a lightning stroke position on the power transmission line, in which a lightning stroke sensor is arranged, and a dedicated database that relates to the lightning current, the voltage induced by the lightning and the lightning stroke position is established to identify the lightning stroke event on the power transmission line. However, the aforementioned methods for identifying and locating the lightning stroke events are based on electronic sensors, which do not use any optical fiber resources in the optical fiber composite overhead ground wire. Therefore, the present invention provides a distributed optical fiber temperature sensor based method to identify and locate the lightning stroke events on the optical fiber composite overhead ground wire, which can make full use of the optical fiber resources and the high-sensitivity detection and high-precision event location capability of the distributed optical fiber temperature sensor, to monitor the temperature suddenly rising point or section along the optical fiber composite overhead ground wire in real time, and analyze temperature change processes of the suddenly rising point or section at different moments and temperature change features at positions adjacent to the temperature suddenly rising point or section, so as to accurately identify and locate the lightning stroke event.